To some teachers, professional development is seen as a burden and not as a chance to improve their practice as the reforms have intended. To this end, this study meant at identifying the public school and private institute EFL teachers' perception towards self-initiated professional development in Iran. Using random cluster sampling, Professional Development Questionnaire was filled out by 82 teachers (working either in private language institutions or public schools) to examine the perceptions of Iranian EFL teachers toward their professional development. Furthermore, this study aimed to explain what major professional development activities English language teachers perceive as critical to their development as professionals and to what degree they make use of these opportunities. This study also investigated if there is any significant difference between the perceptions of Iranian public school and private institute language teachers with regard to the concept of professional development in terms of their gender. Finally, this study investigated the obstacles that might have caused some problems for public and private English language teachers regarding their professional development. The findings revealed key differences in these two groups in terms of motivational factors, gender inclination towards teaching profession, the obstacles they face and the activities they are engaged at to enhance their professional development. The possible reasons behind these differences have been discussed and implications of the study are presented.